This application claims benefit of International Application Number PCT/EP2005/003974, which was published in English on Oct. 27, 2005.
1. Field of the Invention
The present invention relates to a hard, wear-resistant aluminum nitride based coating, an article coated there with and a method for producing such a coating.
2. Description of the Prior Art
Layers based on Al1-xTixN respectively based on Al1-xTixSiyN are commonly used in a Ti/Al stoichiometry range near the maximum hardness. In the case of TiAlN, this stoichiometry corresponds approximately to Al0.65Ti0.35N. If an Al proportion exceeding these conditions, e.g. 75 to 85 at. % of metals, is selected, both hardness and wear resistance are known to break down rapidly. Essentially the same behaviour has been expected and found for Al1-xCrxN and similar hard materials.
The existing knowledge about this softening is described in T. Suzuki, Y. Makino, M. Samandi and S. Miyake, J. Mater. Sci. 35 (2000), 4193 and A. Hörling, L. Hultman, M. Odén, J. Sjölén, L. Karlsson, Surf. Coat. Technol. 191 (2005) 384 and references cited therein.
A typical coating is further known from JP-A-2003/225809.